If you would’ve asked Jake Johnson ten years ago what he’d be driving or doing for a living, we strongly doubt he’d tell you he’d still be driving his first diesel truck and running his own performance shop for a living. With that said, here he is doing both of those things, living under the trance this 2004 GMC Sierra put him under clear back in 2008. While he never intentionally chose to go down this long road of building the Ultimate Street Fighter, it’s always funny how this diesel addiction leads guys.
After first purchasing the truck in 2008 completely stock, it didn’t take long for Johnson to dive in with a simple four-inch exhaust and Bully Dog PMT tuner with the once-popular Crazy Larry tune. Soon after, a FASS lift pump, Banks bighead wastegate, and some custom EFI Live tunes were added that lead to the demise of the stock Allison transmission and factory turbocharger.
At this point, Johnson was hooked on the horsepower and opted to go full steam ahead on performance upgrades with the addition of some ARP head studs, BD Supermax turbo, built transmission and some 45-percent injector nozzles. At this point, the LB7 was making 550hp and was a blast on the street. After adding a Dual CP3 kit with an Industrial Injection 85-percent pump Johnson started competitively drag racing with the NHRDA and traveled from his home in Blackfoot, Idaho to Phoenix, Arizona in 2010 where he made the semi-final round with consistent 12.60 passes.
Determined to get the truck down into the 11’s at the track, Johnson spent the winter of 2011 doing even more upgrades with a new billet 66mm S300 and started tuning the truck himself which bumped power output up near 700hp. Returning to Speed World racetrack in Phoenix the following year, the truck managed to make 28 passes over a three-day trip running a best of 12.17 at 112mph.
The truck drove 15-hours one way to make that event in Phoenix, took a beating at the track and drove back home without a single issue. Pretty impressive considering it was still the stock engine surviving at those power levels. Johnson enjoyed this combination of parts so much, it stayed virtually untouched until 2014 when the time came to drop in a built engine he’d been working on in his spare time. Still coming up short of that elusive 11-second pass, Johnson knew it’d take a bit more horsepower to get where he wanted to be, which meant billet rods and more fuel was needed.
Using a spare long block he’d rounded up he began by tearing it down and having it fully machined and balanced by Troy’s Engine & Machine of Rigby, Idaho. Johnson assembled the engine himself and used Carrillo billet connecting rods, Mahle Cast race pistons with 16.5:1 compression, ARP main studs, ported heads with Hamilton valve springs, the factory camshaft, a Melling oil pump, and tig-welded water pump.
He also upgraded to a set of PPE exhaust manifolds and a high flow piping kit and Y-bridge from HSP Diesel. Once the truck was back up and running with the new engine, he soon developed some transmission issues that required it to be pulled and gone through once again with some new clutches and valve body adjustments to handle increased power output. At a NADM event in Salt Lake City, Utah in 2015 Johnson ran into some major issue with a lifted injector cup and shattered the P2 planetary assembly inside the Allison.
So, for the third time, the transmission had to come back out and was finally upgraded with just about everything possible to withstand the torture of four-wheel-drive launches at the track. Suncoast billet P2 planetary, billet input shaft, pressure mods and a Suncoast 1055 2500 stall triple disc converter. Now, hoping he had the drive train to back it all, Johnson jumped up to a compound turbo kit that billet 366 and a billet Borg Warner S483 pushing 70lbs of boost through a Mishimoto intercooler. The injectors were also bumped up to 100-percent overs, with the latest SAC nozzle design from Exergy.
While the main focus on the truck was making horsepower, there have been a host of other upgrades done to it through the years like the custom two-tone paint from Bowers Collision in Blackfoot, Idaho. A Goodmark steel cowl hood, Royalty Core grille, and an Agricover Lorado tonneau were also installed at that time.
Blacked out headlights from Spyder and Recon compliment the two-tone color scheme nicely along with the paint to match door handles. The front end was upgraded with Fabtech tie rods and a complete PSIK IFS upgrade kit from Cognito. While sitting at stock height, the truck rides on Fox 2.0 shocks front and rear and has Brake Performance drilled and slotted rotors with stainless Russel brake lines. Outback, Johnson has installed a set of traction bars from T&B Fab and installed an Eaton True Trac differential with a Mag-Hytec cover. While it’s had a handful of tire and wheel packages through the years, it primarily sits on 305/50R20 Toyo Proxes tires wrapped around 20×10 SOTA Novakane death metal wheels.
In the cab, Johnson spruced up the fifteen-year-old interior with some new two-tone leather Katzkin seat covers, a painted dash bezel and a full set of Autometer Cobalt gauges and an Edge CTS2 Insight for watching engine vitals. The sound system has been upgraded with a Pioneer head unit and Rockford Fosgate speakers.
Once, this combo had a chance to get dialed in, Johnson was able to pull a personal best time of an 11.11 at 124mph on fuel only. His best dyno chart to date shows 1016hp and 1680 lb-ft of torque, which has been more than enough to meet his long term goals for the truck as the ultimate street fighter.
After over a decade of ownership and dozens of power combos, the truck is still used as his primary daily driver with over 18,000 miles on the built engine and last transmission build. Johnson has been addicted to diesel performance for quite some time and runs Diesel Mafia Performance in Blackfoot, Idaho where he’s been able to use his experiences gained with this truck to help locals build the trucks of their dreams as well. It’s so awesome to see someone’s love for the sport and a vehicle stand the test of time as this old Duramax has for Johnson.
Even after a decade of competing in this truck, you’ll never hear Johnson make an excuse to miss out on a local dyno event or dirt drag going on at the local county fair. This may not be the only truck parked in his garage, with a 4th Gen Mega Cab and a 2016 LML Duramax more recently getting love from Johnson, but you can bet that 10+ relationship carries the most memories and stories, besides with 1000-plus horsepower on tap, we’re positive it’s still the most fun to cruise in on a cool summer evening.